From 3e1bb53c1b8ec0d17ed3b494fc920374892faf3d Mon Sep 17 00:00:00 2001
From: Nikita Vilunov <nikita@vilunov.me>
Date: Tue, 21 Mar 2023 01:16:02 +0100
Subject: [PATCH] feat(xmpp): respond to unknown IQs with errors

---
 src/projections/xmpp/mod.rs   | 15 +++++++++++++++
 src/projections/xmpp/proto.rs | 13 +++++++++++--
 src/protos/xmpp/client.rs     |  2 +-
 src/util/xml.rs               |  8 ++++----
 src/util/xml/ignore.rs        |  2 +-
 5 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/src/projections/xmpp/mod.rs b/src/projections/xmpp/mod.rs
index 846d249..3aefb68 100644
--- a/src/projections/xmpp/mod.rs
+++ b/src/projections/xmpp/mod.rs
@@ -333,6 +333,21 @@ async fn socket_final(
                             }
                             xml_writer.get_mut().flush().await?;
                         }
+                        proto::IqClientBody::Unknown(_) => {
+                            let mut events = vec![];
+                            let req = Iq {
+                                from: None,
+                                id: iq.id,
+                                to: None,
+                                r#type: xmpp::client::IqType::Error,
+                                body: (),
+                            };
+                            req.serialize(&mut events);
+                            for i in events {
+                                xml_writer.write_event_async(i).await?;
+                            }
+                            xml_writer.get_mut().flush().await?;
+                        },
                     },
                     proto::ClientPacket::Message(_) => todo!(),
                     proto::ClientPacket::Presence(p) => {
diff --git a/src/projections/xmpp/proto.rs b/src/projections/xmpp/proto.rs
index 2337868..008c77d 100644
--- a/src/projections/xmpp/proto.rs
+++ b/src/projections/xmpp/proto.rs
@@ -15,6 +15,7 @@ pub enum IqClientBody {
     Bind(BindRequest),
     Session(Session),
     Roster(RosterQuery),
+    Unknown(Ignore),
 }
 
 #[derive(From)]
@@ -26,6 +27,7 @@ enum IqClientBodyParserInner {
     Bind(<BindRequest as FromXml>::P),
     SessionV(<Session as FromXml>::P),
     RosterV(<RosterQuery as FromXml>::P),
+    UnknownV(<Ignore as FromXml>::P),
 }
 
 impl FromXml for IqClientBody {
@@ -58,12 +60,16 @@ impl Parser for IqClientBodyParser {
                 match_parser!(IqClientBodyParser, name, namespace, event;
                     BindRequest,
                     Session,
-                    RosterQuery
+                    RosterQuery,
+                    {
+                        IqClientBodyParser(Ignore::parse().into()).consume(namespace, event)
+                    }
                 )
             }
             Bind(p) => delegate_parsing!(p, IqClientBodyParserInner, namespace, event),
             SessionV(p) => delegate_parsing!(p, IqClientBodyParserInner, namespace, event),
             RosterV(p) => delegate_parsing!(p, IqClientBodyParserInner, namespace, event),
+            UnknownV(p) => delegate_parsing!(p, IqClientBodyParserInner, namespace, event),
         }
     }
 }
@@ -112,7 +118,10 @@ impl Parser for ClientPacketParser {
                 match_parser!(ClientPacketParser, name, namespace, event;
                     Iq::<IqClientBody>,
                     Presence::<Ignore>,
-                    Message
+                    Message,
+                    {
+                        Continuation::Final(Err(ffail!("Unexpected XML event of name {:?} in namespace {:?}", name, namespace)))
+                    }
                 )
             }
             IqV(p) => delegate_parsing!(p, ClientPacketParserInner, namespace, event),
diff --git a/src/protos/xmpp/client.rs b/src/protos/xmpp/client.rs
index 868fc78..6834947 100644
--- a/src/protos/xmpp/client.rs
+++ b/src/protos/xmpp/client.rs
@@ -97,7 +97,7 @@ impl Parser for MessageParser {
                     } else if bytes.name().0 == b"body" {
                         Continuation::Continue(InBody(state).into())
                     } else {
-                        Continuation::Final(Err(ffail!("Unexpected XML tag")))
+                        Continuation::Final(Err(ffail!("Unexpected XML event: {event:?}")))
                     }
                 }
                 Event::End(_) => {
diff --git a/src/util/xml.rs b/src/util/xml.rs
index 98f48a3..1c52549 100644
--- a/src/util/xml.rs
+++ b/src/util/xml.rs
@@ -59,18 +59,18 @@ macro_rules! delegate_parsing {
 }
 
 macro_rules! match_parser {
-    ($outer: ident, $name: expr, $ns: expr, $event: expr; $subtype: ty) => {
+    ($outer: ident, $name: expr, $ns: expr, $event: expr; $subtype: ty, $fin: block) => {
         if $name.0 == <$subtype as FromXmlTag>::NAME.as_bytes() && $ns == ResolveResult::Bound(Namespace(<$subtype as FromXmlTag>::NS.as_bytes())) {
             $outer(<$subtype as FromXml>::parse().into()).consume($ns, $event)
         } else {
-            Continuation::Final(Err(ffail!("Unexpected XML event of name {:?} in namespace {:?}", $name, $ns)))
+            $fin
         }
     };
-    ($outer: ident, $name: expr, $ns: expr, $event: expr; $subtype: ty, $($rest: ty),+) => {
+    ($outer: ident, $name: expr, $ns: expr, $event: expr; $subtype: ty, $($rest: ty),+, $fin: block) => {
         if $name.0 == <$subtype as FromXmlTag>::NAME.as_bytes() && $ns == ResolveResult::Bound(Namespace(<$subtype as FromXmlTag>::NS.as_bytes())) {
             $outer(<$subtype as FromXml>::parse().into()).consume($ns, $event)
         } else {
-            match_parser!($outer, $name, $ns, $event; $($rest),*)
+            match_parser!($outer, $name, $ns, $event; $($rest),*, $fin)
         }
     };
 }
diff --git a/src/util/xml/ignore.rs b/src/util/xml/ignore.rs
index 342e51e..4fe39e5 100644
--- a/src/util/xml/ignore.rs
+++ b/src/util/xml/ignore.rs
@@ -43,7 +43,7 @@ impl Parser for IgnoreParser {
                         )
                     }
                 }
-                _ => Continuation::Final(Ok(Ignore)),
+                _ => Continuation::Continue(IgnoreParserInner::InTag { name, depth }.into()),
             },
         }
     }